Combine two different select and update statements

Question

I have one select query and one update query and I want to combine both of them.

The select query is like:

select questionDesc from myTable
where 
  questionId >= (
    select currentQuestionid from userTable 
    where userId='1'
  )
  and questionId <= (
    select currentQuestionid+4 from userTable 
    where userId='1'
  )

For user=1 , this query tries to fetch all the question Descriptions from myTable whose questionId lies between currentQuestionid and currentQuestionid+4 ( currentQuestionid is a column specific to a user in the userTable ). I will later use this result in my front-end.

Now, I want to update the currentQuesionid to currentQuestionid+5 . This could be achieved using:

UPDATE userTable SET currentQuesionid = currentQuestionid+5 WHERE userId ='1'

I want to achieve both these queries in one database hit so as to improve the performance.

Is there any way to combine the two. I am using WAMP and the code is written in php scripts.

Any help is appreciated.

Answer 1

I think I have found the answer.

For combining multiple queries together we can use mysqli_multi_query() function. It is available for MySQL server versions 4.1.3 and newer. It takes multiple queries as input parameter and performs them in one db hit .

for example:

 //sql queries should be separated by semi-colons $sql = "SELECT Lastname FROM Persons ORDER BY LastName;"; $sql .= "SELECT Country FROM Customers"; // Execute multi query if (mysqli_multi_query($con,$sql)) { do { // Store first result set if ($result=mysqli_store_result($con)) { // Fetch row one and one while ($row=mysqli_fetch_row($result)) { printf("%s\\n",$row[0]); } // Free result set mysqli_free_result($result); } } while (mysqli_next_result($con)); } 

Source: http://www.w3schools.com/php/func_mysqli_multi_query.asp